Financial Instruments and Fair Value Measurements - Fair Values of Financial Instruments (Detail) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014
Assets
Institutional money market investments	$ 6,809	$ 1,040
Interest rate swaps	10	3
Forward exchange contracts	22	20
Total Assets	6,840us-gaap_AssetsFairValueDisclosure	1,063us-gaap_AssetsFairValueDisclosure
Liabilities
Forward exchange contracts	16	14
Contingent consideration liabilities	50	14
Total Liabilities	67us-gaap_LiabilitiesFairValueDisclosure	29us-gaap_LiabilitiesFairValueDisclosure
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Assets
Institutional money market investments	6,809	1,040
Total Assets	6,809	1,040
Significant Other Observable Inputs (Level 2) [Member]
Assets
Interest rate swaps	10	3
Forward exchange contracts	22	20
Total Assets	32	23
Liabilities
Forward exchange contracts	16	14
Total Liabilities	16	14
Significant Unobservable Inputs (Level 3) [Member]
Liabilities
Contingent consideration liabilities	50	14
Total Liabilities	$ 50	$ 14

Fair value of contingent consideration liabilities recognized as part of business combination transaction.

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- Definition

Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (a)

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- Definition

Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Cash

-URI http://asc.fasb.org/extlink&oid=6506951

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Cash Equivalents

-URI http://asc.fasb.org/extlink&oid=6507016

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- Definition

Fair value portion of asset contracts related to the exchange of different currencies, including, but not limited to, foreign currency options, forward contracts, and swaps.

+ References

No definition available.

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Fair value portion of liability contracts related to the exchange of different currencies, including, but not limited to, foreign currency options, forward (delivery or nondelivery) contracts, and swaps entered into.

+ References

No definition available.

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- Definition

Fair value as of the balance sheet date of interest rate derivative assets, which includes all such derivative instruments in hedging and nonhedging relationships that are recognized as assets.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 825

-SubTopic 10

-Section 50

-Paragraph 10

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=35750535&loc=d3e13433-108611

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- Definition

Fair value of financial and nonfinancial obligations.

+ References

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